Jerry Yang, co-founder and former CEO of Yahoo, will be retiring from Cisco Systems board of directors in November, the company announced in a regulatory filing.

Yang will be stepping down "to more fully pursue new personal and business interests," the filing stated. Yang will continue to serve as a director until Cisco's 2012 Annual Meeting of Shareholders to be held on Nov. 15, but he will not stand for re-election.

Following Yang's announcement, Cisco Systems said it will reduce the size of its board to thirteen members, effective upon Yang's retirement.